Mybatis在执行存储过程时无法设置OUT参数

Question

I am following this question to call a stored procedure with 1 input parameter and 1 out parameter:

Mapper:

package myapp.test.persistence;

import myapp.test.ExpectationProcessMessage;
import org.apache.ibatis.annotations.*;

import java.util.List;
import java.util.Map;

@Mapper
public interface ExpectationProcessMessageMapper {
    List<ExpectationProcessMessage> processExpectation(Map<String, Object> params);
}

XML content:

<mapper namespace="myapp.test.persistence.ExpectationProcessMessageMapper">

    <resultMap id="expectationProcessMessages" type="myapp.test.ExpectationProcessMessage">
        <id property="errorCode" column="error_code"/>
        <result property="errorMessage" column="error_message"/>
    </resultMap>

    <select id="processExpectation" parameterType="java.util.HashMap" resultMap="expectationProcessMessages">
      {call cp_process_expectation_api (#{ai_expectation_id,jdbcType=NUMERIC, javaType=java.lang.Integer,mode=IN},
                                         #{ac_process_flag,jdbcType=VARCHAR, javaType=java.lang.String,mode=OUT})}
    </select>
</mapper>

Call class:

package myapp.test.persistence;

@Repository
public class SqlExpectationRepositoryImpl implements ExpectationRepository {
    ...
    @Override
    public ExpectationProcess processExpectation(Integer expectationId) {
        Map<String, Object> params = new HashMap<String, Object>();
        params.put("ai_expectation_id", expectationId);
        params.put("ac_process_flag", null);
        List<ExpectationProcessMessage> expectationProcessMessages = expectationProcessMessageMapper.processExpectation(params);
        System.out.println(params.get("ac_process_flag"));
    }
    ...
}

Stored procedure definition:

begin
    declare @ai_expectation_id int = 0
    declare @ac_process_flag char
    declare @result int
    exec
        @result = cp_process_expectation_api
            @ai_expectation_id,
            @ac_process_flag output

    select @ac_process_flag

    select @result as result
end

But I got an exception:

Cause: com.microsoft.sqlserver.jdbc.SQLServerException: The value is not set for the parameter number 2.
Uncategorized SQLException; SQL state [null]; error code [0]; The value is not set for the parameter number 2.; nested exception is com.microsoft.sqlserver.jdbc.SQLServerException: The value is not set for the parameter number 2.

Answer 1

I have found the solution. We need to add statementType="CALLABLE" property to XML file. It will be like this:

<mapper namespace="com.gbst.processmanagement.infra.persistence.expectation.expectation.ExpectationProcessMessageMapper">

    <resultMap id="expectationProcessMessages" type="com.gbst.processmanagement.domain.expectation.expectation.ExpectationProcessMessage">
        <id property="errorCode" column="error_code"/>
        <id property="messageType" column="message_type"/>
        <result property="errorPointer" column="error_pointer"/>
        <result property="errorMessage" column="error_message"/>
    </resultMap>

    <select id="processExpectation" statementType="CALLABLE" parameterType="java.util.HashMap" resultMap="expectationProcessMessages">
      {call cp_process_expectation_api (#{expectationId,jdbcType=NUMERIC, javaType=java.lang.Integer,mode=IN},
                                        #{processFlag,jdbcType=VARCHAR, javaType=java.lang.String,mode=OUT})}
    </select>
</mapper>